1. March 1, Math 201
OBJECTIVE: Students will be able to use substitution to evaluate algebraic expressions, including exponents of one, two, or three
AIM: How can we use the order of operations to help us evaluate algebraic expressions?
STANDARDS: 6.A.2
PRIOR KNOWLEDGE: Write as an algebraic expression
Five more than some number, n
Three less than some number times two

2. When we evaluate an expression, we SUBSTITUTE some value for the variable.
“SUBSTITUTE” means “TO REPLACE”
Example: n + 5, when n = 3
Rewrite the expression, and substitute for n
3 + 5
We can now evaluate the expression by doing the math: is 8

3. Example: Evaluate n2 – 5, when n = 6
1. Rewrite, using substitution
2. Do the math, using order of operations
62 – 5 is the same as
36 – 5, which is 31
Example: Evaluate 5x2 + 9
(NOTE: the exponent goes with the variable ONLY)
Rewrite, using substitution
2. Do the math using order of operations

4. Example: Evaluate 2y3 + 5, when y = 2
Rewrite, using substitution
Do the math using order of operations

5. INDEPENDENT WORK
What is the value of the expressions?
n + 4 when n = 3
2y – 5 when y = 7
3n2 + 3 when n = 2
a3 when a = 3
2n2 – 6 when n = 5
HOMEWORK: Handout